Over the last decade, with the advent of the web interface to mail, email-based communication has become a major method of human interaction in the digital world. An email address has increasingly become an important digital identity for many online activities e.g., communicating with friends, participating in discussion groups, and shopping on the web.
However, along with the benefits, email-based communication has come several negative aspects. For example, today, unsolicited and unwanted email (spam) has become a wide spread problem due in part to the ease and low cost of sending spam to millions of email addresses. These unwanted emails waste the time, money, and resources of end users and service providers. In the past, there have been relatively low barriers to spamming, making it difficult to filter out the unsolicited, unwanted messages. Thus, it is with respect to these considerations and others that the present invention has been made.